Suction accumulator



May 13, 1969 E. w. BOTTUM 3,443,367

SUCTION ACCUMULATOR Filed March 10, 1967 Sheet of 2 INVENTOR.

EDWARD W BOTTUM. BY

WILSON, SETTLE, BATCHELDER ATT'YS. ORA/6 y 1969 E. w. BOTTUM 3,443,367 sucnou ACCUMULATOR Filed March 10, 19s? Sheet 3 of 2 JNVENTOR.

EDWARD W. BOTTUM WILSON, SETTLE, BATCHELDER ATT'YS. a CRAIG.

United States Patent 3,443,367 SUCTION ACCUMULATOR Edward W. Bottum, 9357 Spencer, Brighton, Mich. 48116 Filed Mar. 10, 1967, Ser. No. 622,125 Int. Cl. Btlld 53/04, 53/14 US. Cl. 55-316 9 Claims ABSTRACT OF THE DISCLOSURE A suction accumulator has a casing with two oppositely disposed openings and a tube extending through both openings. Refrigerant fluid enters the casing through the inlet end of the tube outside the casing and passes through perforations in the tube after it enters the casing. A cap on the other end of the tube can be removed to permit access to the tube. A purifying element is provided in the tube such as a dessicant and/ or strainer for removing particles. A U-shaped outlet conduit under suction has one opening for exhausting gases from the casing and another near the casing bottom for withdrawing liquid at a controlled rate.

Background of the 'invention The present invention relates to a suction accumulator for a refrigeration system, and more particularly to a suction accumulator incorporating a drier or a strainer.

An accumulator of the type with which the present invention is concerned is provided between the compressor and evaporator of a refrigeration system to trap any liquid refrigerant emanating from the evaporator and feed this liquid refrigerant to the compressor at a metered rate. The feeding is accomplished by means of the suction created by the compressor. Feeding of the liquid refrigerant back to the compressor at a metered rate prevents large amounts of liquid refrigerant from suddenly entering the compressor. Such sudden surges of liquid often result in seriously damaging the compressor. The accumulation of large amounts of liquid refrigerant in the accumulator may occur, for example, after the system has been shut down.

Summary of the invention In accordance with the present invention, a drier assembly may be provided in the accumulator to remove moisture from the refrigerant. Small amounts of moisture in the refrigerant can damage the various components of the refrigeration system, The provision of a drier on the low pressure side of the refrigeration system is desirable in that the drier is more effective on the low side than it is on the high side. This permits a much smaller amount of dessicant to be used in the drier. For some applications, the drier may be omitted and a strainer provided in the accumulator instead, whereas for other applications, a drier and a strainer are used together.

It is, therefore, an object of the invention to provide a suction accumulator which incorporates an improved drier and/ or strainer assembly.

Another object of the invention is to provide such a suction accumulator which is particularly useful in systems which are operated intermittently such as heat pumps, air conditioning systems and other commercial refrigeration systems.

A further object of the invention is to provide an accumulator with a drier assembly which may be easily removed for cleaning or replacement.

Another object of the invention is to provide a drier assembly forming part of the inlet to the accumulator, the inlet structure preventing a pressure drop of incoming refrigerant gas.

A further object of the invention is to provide a strainer at the inlet of the drier assembly which is capable of shifting in the event of plugging to thereby always maintain the inlet open.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

In the drawings:

FIGURE 1 is a side elevational view in section of one embodiment of the suction accumulator of the present invention;

FIGURE 2 is a sectional view in perspective of the suction accumulator of FIGURE 1 with the drier assembly exploded;

FIGURE 3 is a sectional view of another embodiment of the invention; and

FIGURE 4 is a sectional view of still another embodiment of the invention.

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.

As illustrated in FIGURE 1, the suction accumulator 10 includes a casing 12 which comprises an open ended tube 14 having an upper end closure 16 and a lower end closure 18 secured thereto. A threaded stud 20 is provided on the lower end closure 18 for securement of the accumulator to a supporting structure.

An inlet tube 22 extends through the side of the casing 12. The inlet tube 22 contains the drier assembly of one embodiment of the present invention. An outlet tube 24 extends through the upper end closure 16. The outlet tube 24 is U-shaped. One leg 26 of the tube 24 extends downwardly to a point adjacent the lower end closure 18. The tube is then provided with a bend 28 and the second leg 30 extends upwardly and terminates in an open end 32 adjacent the upper end closure 16.

A small metering opening 34 is provided in the tube bend 28.

In operation of the accumulator, cool refrigerant gas having entrained liquid refrigerant therein enters the accumulator through the inlet tube 22. The refrigerant gas is drawn into the open end 32 of the U-tube 24, passes through both legs of the U-tube and exits through the outlet and thence to the compressor. The compressor, which creates a suction, draws the gaseous refrigerant through the accumulator at a relatively rapid rate.

Liquid refrigerant which enters the accumulator through the inlet tube 22 drops to the bottom of the accumulator and is subsequently drawn through the opening 34 and thence through the leg 26 into the compressor. The opening 34 acts as a restriction and causes the liquid refrigerant to be metered into the compressor at a controlled rate. The accumulator thus acts to prevent large amounts of liquid refrigerant from suddenly entering the compressor. Such sudden surges of liquid may result in seriously damaging the compressor.

Referring now to the drier assembly, it will be noted that the inlet tube 22 extends entirely through both walls of the tubular portion 14 of the casing. One projecting portion 36 forms the inlet for refrigerant gas. The other projecting portion 38 serves as an inlet for access to the drier assembly.

It will be noted that the drier assembly includes a tubular foraminous element 40 having a cup-shaped tubular end piece 42 at one end for abutment against inwardly tapering portion 44 of the inlet end of the tube 22. A foraminous wall 46 is provided within element 40 a substantial distance from the end piece 42. Thus, the portion 48 of foraminous element 40 is entirely open to permit incoming refrigerant gases to freely pass therethrough without a pressure drop. Openings 50 are provided in the inlet tube 22 around the portion 48 to permit refrigerant gases to pass therethrough and into the casing 12 for eventual movement through the U-tube 24 to the compressor of the system.

One feature of the inlet thus described is that the incoming fluids which are moving at a relatively high velocity, impinge against the wall portion 46 and in general expand circumferentially with respect to the portion 48. This results in a reduction in the velocity of the fluids and also in movement of the fluids into the casing 12 in a fan-like pattern as opposed to a discrete jet. As a consequence, incoming fluids will not be directed as a high speed jet against any liquid which may be retained in the casing 12. This prevents turbulence of the liquid which may result in foaming and also prevents splashing of liquid into the open end 32 of the U-tube. The introduction of liquid into the U-tube by splashing is undesirable because it is desired to control the rate at which liquid enters the U-tube.

Cup-shaped end piece 62 is provided in the opposite end of the foraminous element. The end piece 62 includes a closure element 54 which blocks this end of element 40. Desiccant material 56 is provided between the closure 54 and wall portion 46. The desiccant material may be any conventional drier material, such as silica gel. The desiccant may be in granular form or may be in block form. Further the desiccant may be charged into the element 40 in a loose state or may be contained in either a wire or fabric material to form a pillow. The use of a pillow structure is a precaution against desiccant powder falling through the foraminous element 40 and mixing with the liquid refrigerant.

The outer end of the projecting portion 38 is provided with an externally threaded ring 58. An internally threaded cup-shaped closure 60 is threaded onto the member 58 to secure the assembly in place. An annular sealing member 63 is provided to seal the juncture of the closure 60 and member 58.

A coil spring 64 is provided in portion 38 to urge the foraminous element 40 inwardly. An offset pin 66 is secured to the element 54. The inner end of the spring 64 extends beneath the pin 66. This connection permits ready withdrawal of the element 40 when it is to be cleaned or the desiccant replaced.

A plurality of openings 68 are provided in tubular member 22 around the desiccant material to permit circulation of refrigerant gases through the desiccant.

A small opening 70 is provided in the inlet 26 at substantially the level of the end 32 of the leg 30. The function of the opening 70 is to equalize the gas pressure within both legs 26, 30. This is of importance when the accumulator has a large amount of liquid therein, as while the system is on the 01f cycle but pressure is gradually building up in the evaporator. The liquid which is within the U-tube 24 could be forced out of the tube and into the compressor as a single slug if the pressures were not equalized within the legs 26, 30 during the off cycle.

In operation of the accumulator 10, gaseous refrigerant 4 containing entrained liquid refrigerant enters the inlet tube 22 and freely flows through portion 48 into the casing 12. The free flow of gaseous refrigerant is of importance in that there is substantially no pressure drop of the incoming gas. Any large pressure drop would result in a loss of capacity. Additionally, by initially injecting the refrigerant gas into the casing and permitting the gas to subsequently flow through the desiccant, rather than passing the gas directly through the desiccant, is advantageous in that there is no turbulence and powdering of the desiccant. All of the gas in the system, as it recirculates eventually passes through the desiccant 56 for removal of moisture therein.

If the strainer portion 48 of the element 40 ever becomes plugged, the pressure of the incoming gas can cause the element 40 to move against the spring 64 and open a passage for incoming gas between the end piece 42 and the portion 36 of tube 22. Thus, the strainer will never completely stop flow of refrigerant gas into the accumulator.

An advantage of the drier construction of FIGURES 1 and 2, in addition to the easy removability of the element 40 for cleaning the strainer or changing the desiccant, is that the suction accumulator may be installed as a part of a refrigeration system without the element 40 in place. The system may then be dehydrated and the element 40 with a dry desiccant cartridge then inserted. This eliminates the necessity of having to bake the desiccant along with the remainder of the system.

A further advantage in the drier assembly illustrated in FIGURES 1 and 2 is that the drier is provided on the low pressure side of the refrigeration system. This permits the use of a much smaller amount of desiccant than would be necessary if the drier were located on the high pressure side. For example, the amount of desiccant used may be only one-third as much as would be used if the drier Were on the high pressure side of the refrigeration system.

A modification of the invention Which forms another embodiment is shown in FIGURE 3. In this embodiment, the suction accumulator has a casing including a tubular body 102 closed at its bottom end by a closure member 104 and closed at its top end by a closure member 106.

An inlet tube 108 extends vertically through the casing 100 and projects through opposed openings in the casing, one such opening 110 being located in the top closure 106 and the other opening 112 being located in the bottom closure 104. An outlet tube 114 extends through the top closure 106. The outlet tube 114 is U-shaped. One leg 116 of tube 114 extends downwardly to a point next to the bottom closure 104, and the tube bends around to a second leg 118 which extends upwardly and terminates in an open end 120 adjacent the top closure 106. A small metering opening 122 is provided in the tube bend 124.

The overall operation of the suction accumulator of FIGURE 3 is very similar to that of the embodiment of FIGURES 1 and 2. Cool refrigerant gas having a small amount of liquid refrigerant entrained therein enters the accumulator through the inlet tube 108. The compressor, which is connected to leg 116 of tube 114, creates a suction in tube 114. The refrigerant gas is drawn into the open end 120 of tube 114, passes through both legs of the U-tube, and goes to the compressor. Refrigerant liquid which enters the accumulator through the inlet tube 108 drops to the bottom of the accumulator and is drawn through the metering opening 122 into leg 116 of the U-tube 114 and from there to the compressor. This liquid is thus metered to the compressor at a controlled rate.

The inlet tube 108 of the drier assembly extends longitudinally of the casing 100 in the embodiment of FIG- URE 3 rather than transversely as in FIGURES 1 and 2. There are other diiferences too. No strainer is provided in the tube 108 and consequently a spring is not needed. Inside the tube 108 is a pillow 120 comprising a fabric or wire mesh bag containing a charge of desiccant such as silica gel. This desiccant charge removes water from incoming fluids by absorption. A spacer 123 is located between pillow 1'20 and an end cap 128. The sleeve 123 keeps the pillow from entering the space next to cap 128. The bottom end of tube 108 is threaded at 126 to threadingly receive the cap 128 which seals the end of the tube. The cap 128 is removable to give access to the interior of tube 108, for example, to insert and withdraw the pillow 120.

FIGURE 4 illustrates another embodiment of the invention in which both the inlet tube 130 and the U-sh-aped outlet tube 132 extend transversely of the casing 134, and in which the casing is to be mounted with its axis extending horizontally. The casing includes a tubular body 136 and two end closures 138 and 140. Outlet tube 132 has one leg 142 which extends into tubular body 136 at an opening 144, and bends around so that the bend portion 146 is next to tubular body 136 opposite opening 14'4. The other leg -148 of tube 132 extends upward from bend portion 146 and terminates short of tubular body 136. The end 150 of leg 148 is open. When the compressor applies suction to the outlet tube 1B2, refrigerant gas is drawn into the open end 150, passes through leg 148, bend 14'6, leg 142 and from there to the compressor. Liquid is drawn into tube 132 through a small opening 152 located in the bend portion 146 of the tube 132. Opening 1'52 acts as a restriction and meters only a small, controlled amount of liquid into tube 132. This liquid is drawn to the compressor along with the gas introduced at open tube end 150.

Refrigerant gas containing a small amount of refrigerant liquid entrained therein is supplied to the interior of casing 134 through an inlet tube 130. The inlet tube 130* extends across tubular body 136 and projects through two openings 1'58 and 160 located opposite each other in tubular body 136. One projecting portion 162 of tube 130 serves as the inlet through which refrigerant gas and some refrigerant liquid are introduced into casing 134. The other projecting portion 164 of tube 130 can be opened to provide access to the interior of tube 130. The tube 130 has openings 166 extending through it through which gas and liquid refrigerant is delivered to the casing interior. Inside of tube 130 there is an elongated foraminous tube 168 which acts to strain particles from the incoming fluids. A solid wall 170 may be placed across the strainer tube to deflect refrigerant fluids toward the casing interior in a fan-like pattern and not as a discrete jet.

It will be noted that no drier is provided within inlet tube 130, and also the spring 64 and associated structure have been omitted. Only a strainer is provided in tube 130 for purification of incoming fluids.

Having thus described my .invention, I claim:

1. A refrigeration component comprising a casing defining a closed chamber to serve as a suction accumulator for the compressor of a refrigeration system for receiving refrigerant gas having a small amount of liquid entrained therein, said casing having a pair of oppositely disposed openings therein, one of said openings providing an inlet opening for refrigerant fluid and the other of said openings providing for access to the interior of said casing, a tubular member extending between and through said openings, a detachable sealing element on said tubular member closing the other of said open-ings, said tubular member having perforations therein for free circulation of refrigerant gas between the interior of said tubular member and the casing interior, said perforations being of a size sufficient to obviate a substantial pressure drop upon passage of refrigerant gas therethrough, purifying means in said tubular member for removing impurities from incoming refrigerant fluid, said purifying means being removable through the other of said openings after removal of the detachable sealing element, said purifying means being constructed and positioned to provide free passage of gaseous refrigerant adjacent to the inlet opening to obviate a substantial pressure drop upon passage of refrigerant gas therethrough, said casing having an outlet, and conduit means extending from said outlet into said casing, said conduit means including opening means for freely exhausting gases from the casing interior and opening means adjacent the casing bottom for drawing liquid from the casing at a controlled rate.

2. A refrigeration component as claimed in claim 1, in which said purifying means includes a desiccant charge in said tubular member for removing water from incoming refrigerant fluid, said desiccant charge being located away from said inlet opening.

3. A refrigeration component as claimed in claim 1, in which said purifying means includes a foraminous strainer within said tubular member for removing particles from incoming refrigerant fluids, said strainer being located adjacent to the inlet whereby all incoming refrigerant fluid must pass therethrough.

4. A refrigeration component as claimed in claim 1, in which said purifying means includes a desiccant charge in said tubular member for removing water from incoming refrigerant fluids, said desiccant charge being located away from said inlet opening, said purifying means further including a foraminous strainer within the tubular member for removing particles from incoming refrigerant fluids, said strainer being located adjacent to said inlet opening whereby all incoming refrigerant fluid must pass therethrough.

5. A device as defined in claim 4, and further characterized in that said foraminous strainer extends between said pair of oppositely disposed openings in the casing, said desiccant charge being provided in said foraminous element and terminating short of the inlet opening to provide a space at the inlet for dissemination of incoming refrigerant fluid into the casing interior.

6. A device as defined in claim 5, and further characterized in the provision of a wall within the foraminous strainer adjacent to the inlet opening to define a space at the inlet for dissemination of incoming refrigerant fluid into the casing interior.

7. A device as defined in claim 3, and further characterized in the provision of spring means between the detachable sealing element and the foraminous strainer, said spring means biasing the foraminous strainer towards the inlet opening.

8. A device as defined in claim 5, and further characterized in the provision of a cup-shaped element at each end of the foraminous strainer, the cup-shaped element at the inlet having opening means for flow of incoming refrigerant fluid therethrough into the foraminous strainer, the cup-shaped element at the opposite end of the foraminous strainer being closed to prevent flow of refrigerant gas thereby.

9. A refrigeration component comprising a casing defining a chamber to serve as a suction accumulator for the compressor of a refrigeration system for receiving refrigerant gas having a small amount of liquid refrigerant entrained therein, said casing including a side wall structure, said side wall structure having a pair of oppositely disposed openings, one of said openings being an inlet for refrigerant fluid, a detachable sealing element on the other of said openings, a first tubular member extending between said oppositely disposed openings, a second removable tubular foraminous element means within said first tubular member, a desiccant charge in said foraminous element, said desiccant charge terminating short of the inlet opening to provide a space at'the inlet for free dissemination of incoming refrigerant fluid into the casing interior, said first tubular member having perforations therein for the free circulation of refrigerant gas between the casing interior and the interior of the first tubular member, said perforations being of a size suflicient to obviate a substantial pressure drop upon passage of refrigerant gas 7 8 therethrough, said foraminous strainer being removable References Cited from the casing upon removal of said detachable sealing UNIT D STATES PAT NTS element, spring means between the detachable sealing ele- 1,506,967 9/1924 Bosworth ment and the foraminous strainer, said spring means 3,126,335 3/1964 Stipe 210-266 X biasing the foraminous element towards the inlet opening, 5 3,212,289 10/1965 Bottllm 62503 X said casing having an outlet, and conduit means extending 12 2::

from said outlet into the casing, said conduit means including opening means for freely exhausting gases from REUBEN FRIEDMAN, Primary Examine"- the casing interior and opening means adjacent the casing 10 R. W. BURKS, Assistant Examiner.

bottom for drawing liquid from the casing at a metered CL rate. 55387 

